Allows you to use Vim-interface from within IntelliJ IDEA.
You get the code formatting features of Idea, as well as some of the cooler shortcut keys, and still get to keep the main Vim keyboard movements.
You can navigate Camel-Case words like this:
]b [b ]w ]W ]e [e
etc.
See this link: http://ideavim.sourceforge.net/vim/index.html
I copied the README file from the download.
Control-O is taken by something in IDEA, so it doesn't put the editor into Normal mode for 1 command, like regular Vim does. Kinda sucks, but oh well.
You can't copy stuff into a register using the :redir Ex command. This isn't that big of a deal